Process of producing steel dies.



GEORGE EUNE's DIEZ, OF NEW YORK, 5. r.

PROCESS OF PRODUCING STEEL Dl E S.

Specification of Letters Patent.

Patented June 25, 1907.

Application filed February 5, 1907. Serial No. 355,954.

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Be it known that I, GEORGE FUNEs DIEz, a citizen of the United States, residing at New York, in the county vof New York and I State of New York, have invented a new and useful Process of Producing Steel Dies, of which the following is a specification.

This invention has reference to improvements in the process of producing steel-dies directly from the object to be reproduced without the necessity of engraving the die. 5 The invention consists essentially in depositing iron electrolytically directly upon the surface to be reproduced and then in so treating the iron matrix thus formed as to convert it into a grade of steel best suited for producing positive impressions in the material chosen for the copies of the original.

The improved process is particularly applicable for the reproduction of the finest type I of engraving where faithfulness of the copy is important, since I am enabled to produce directly upon the body to be copied a filmof "exceeding fineness, so fine and homogeneous 2 5 in texture as to produce a deposit which from beginning to end is white like tin and at the same time so free from corrugations, roughness or crystalline structure as to have the softness of silk to the touch. In thisre spect the deposited iron is far superior to copper for the copying of all kinds of metals, coins, etc., and it has the further advantage that the ironcopy can be converted into steel of any degree of hardness so that it may be used directly for making positive copies of the original. v

In carrying out my improved. process, I first prepare a bath by taking 1000 cubic centimeters of a saturated aqueous solution of iron sulfate and 125 cubic centimeters of a saturated aqueous solution of sodium bicar bonate. To prepare this bath, which is to constitute the electrolyte, I first mix with the 1000 cubic centimeters of the saturated solution of iron sulfate but onehalf of the saturated solution of sodium bicarbonate, or 62; cubic centimeters of the latter. The mixture is stir: ed with 'a wooden rod and allowed to stand for twelve hours, after which it is filtered and the remainder of the saturated solution of sodium bicarbonate is added and the bath is then. permitted to stand for twenty-four hours. The electrolyte is placed in a tank or vat of glass, porcelain, varnished 5 5 Wood or other suitable material, and the ob- 1 jects to be plated or copied are hung in the vat and are connected up to a suitable source ofeiectric current so that they constitute the cathode. The anode is composed 'of an iron plate. For the best results the current should range between 0.7 and 1.5 volts, while the densityof the bath must be from' 18 to 20 degrees Baum, and the temperature should be about 21 degrees centigrade if it is desired to deposit the 1netal 6- rapidly, but a temperature as low as 16 de-. grees centigrade is quite practicable.

The molds constituting the cathode are hung by fine copper wire from suitable sup- .ports inthe usual manner and are located from 10 to 25 centimeters from the anode. The deposit of iron begins at once simultaneously over all the surface of the mold and the color is a velvety, metallic white.

It will be understood, of course, that any material which it is desired to copy which in itself is not electro-conducting will be treated so as to form a conducting film over the surface to be copied. The time during which the molds should be kept in the bath will depend upon the desired thickness of metal to be obtained. Under normal conditions a matrix thick enough for type or for seals to' stamp on leather or paper can be obtained in from three to four days, depending on the 8 dimensions, while a matrix to be attached to a block of steel and used as a die to stamp on metals .will require from ten to fifteen days.

In order to separate the deposited metal from the original or master, it is taken from the bath and washed with distilled water, after which, if the mold be metallic, the mold and matrix may be heated and may then be separated by inserting a thin blade between them and carefully prying them apart. If 5- the original be of rubber, a slight heating will be sufficient, while when waxy compositions are used, an immersion in boiling-water is all that is necessary.

The electrolytically deposited iron matrix [00 is too soft for use and must therefore be converted into steel of the requisite hardness. For this purpose I take charcoal powder 8 parts, steel filings 1% parts, potassium ferrocyanid 1- part. To this mixture I add a suiii- To 5 cient quantit of oil to form a paste. The several ingrer ients are all ground together in a mortar and the oil is added in small quan- .tities from time to time until the desired paste is formed. The crucible is half iilled 11o with the paste an the matrix is first wet 7 steel, after which it may be tempered and is ready for use for stamping etals, and will stand the pressure of the ihost powerful presses.

All the details of the original from which the matrix has been produced will be found so perfectly reproduced that retouching is not required. The bath will Work perfectly and regularly for many months and it is only necessary to clean the anode from time to time since it may contain impurities which I will form a black coating and must be to remove the oXid from the body of the.

cleaned off. It is also necessary'from time to time to add some of the saturated solution-of sodiumbicarbonate so as to make 11 losses due to evaporation and tomaintaimt e level ofthe bath. The sodium bicarbona serves liquid, which oxid rises to the surface and there forms a film consistent enough to serve as acover to the bath, thus keeping it "free .fillom such impurities as might reach it from t eair.

I claims 1. Themethod of depositing iron upon-a conducting surface consistin in subjecting the surface to be copied electric current in an electrolyte containing iron sulfate and sodium bicarbonate.

2. The method of depositing iron upon a conductingsurface consisting in subjecting the surface to be copied to the action of an electric current in an electrolyte composed of iron sulfate andsodium bicarbonate, and maintaining the stren th of the bath constant b the presence 0 an iron anode.

3. T e method of producing iron matrices of conducting surfaces consisting in depositing the iron electrolytically upon said surfaces in an electrolyte consisting of a saturated solution of iron sulfate and a saturated solution of sodium bicarbonate.

4. The method of producing iron matrices .of conducting surfaces consisting in depositing the iron electrolytically upon said surfaces in an electrolyte consisting of about eight parts'of a saturated solution of iron su ate and about one part of a saturated solution of sodium bicarbonate.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature. in the presence of two Witnesses.

\ GEORGE FUNES DIEZ.

Witnesses:

F. A. RANELLA, MANUEL Ronmsunz.

to the action of an 

